Verb tenses are central to effective storytelling; it’s no mystery that stories unfold through relaying action. Choosing whether to write a story with verbs in the present, past or combo (past, present and future) is ultimately up to the writer. In storytelling, the form is personal, and it follows that style would be too; there is no prescribed right or wrong. That said, weighing the effectiveness of a variety of verb tenses and keeping them consistent will strengthen your writing. If your story employs a variety of tenses, it is muy importante to keep things organized so it all makes sense.
A story that took place in the past is written most clearly in the past tense. The reader has no question in their mind that what they’re reading has already happened. When writing a story in the past, a sprinkling of the present tense often comes in through dialogue (e.g., Phil walked down the stairs. His buddy Matt tried to trip him. “What’s your problem?” Matt said.). Notice that the actual line of dialogue is spoken in the present, but the verb “to say” is in the past (i.e. “said”). So, using the past tense in storytelling (with a healthy dose of present tense in dialogue) will give readers clarity in regards to contextualizing.
When I am a character in the unfolding story I’m writing, I find myself often utilizing present tense (e.g., I’m walking down the street and this dog comes out of nowhere…). I feel that this technique draws in the reader (or audience) better than just using past tense; present tense creates an immediacy…we’re in the moment (we, meaning me, the narrator and you, the audience) and the action is happening right now. The action is bringing me right back to that moment, and I am in effect reliving it, although this time you are witnessing it with me. I admittedly don’t know if my style would be backed up by any English grammar book, nor do I particularly care. I only know that when I verbally relay stories, I use present tense a lot; I’ve brought that colloquialism to my writing.
Perhaps the most important thing about tenses is to not worry so much about them when you start writing. They are fixed easily, and you can use them however you like. So, get down your story first (perhaps writing the whole thing in the simple past, if applicable) then go back and see where you can play and add some variety. Again, being consistent will make your story more readable and way more awesome. Happy writing!